25644003656 has 8 divisors (see below), whose sum is σ = 48082506870. Its totient is φ = 12822001824.

The previous prime is 25644003607. The next prime is 25644003667. The reversal of 25644003656 is 65630044652.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 25188864100 + 455139556 = 158710^2 + 21334^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-2 number, since 2×25644003656² (a number of 22 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1602750221 + ... + 1602750236.

Almost surely, 2^25644003656 is an apocalyptic number.

It is an amenable number.

25644003656 is a deficient number, since it is larger than the sum of its proper divisors (22438503214).

25644003656 is a wasteful number, since it uses less digits than its factorization.

25644003656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3205500463 (or 3205500459 counting only the distinct ones).

The product of its (nonzero) digits is 518400, while the sum is 41.

The spelling of 25644003656 in words is "twenty-five billion, six hundred forty-four million, three thousand, six hundred fifty-six".